Chacodex

Sun Moon Lake Ruby 18

Red Jade - Taiwan’s signature black tea cultivar (TTES #18), a cross of wild Taiwanese and Burmese tea with a distinctive minty-spice character.

Type
Black Tea
Origin
Taiwan · Nantou
Oxidation
full
Caffeine
medium
Brew temp
90–95°C
Brew time
3–5 min
Flavor notes
mint, cinnamon, malt

History

Sun Moon Lake Ruby 18 (紅玉紅茶), also known as Red Jade or Hong Yu, is Taiwan's most celebrated black tea - a cultivar developed over decades by the Taiwan Tea Research and Extension Station (TTES). Designated TTES #18, it was created by crossing Taiwan's native wild tea (Camellia formosensis) with a Burmese large-leaf variety (Camellia sinensis var. assamica). Released in 1999, it immediately stunned the tea world with its utterly distinctive minty-cinnamon character - a flavor profile found in no other tea on earth. Production is centered around Sun Moon Lake (日月潭) in Nantou County, where the unique microclimate and rich soil provide ideal growing conditions. Ruby 18 single-handedly revived Taiwan's declining black tea industry.

Processing

Full oxidation (95–100%) in the style of premium black teas. After plucking (ideally one bud and two leaves), the leaves are withered for 12–18 hours, then rolled to rupture cell walls and initiate oxidation. The oxidation period is carefully controlled - typically 3–5 hours in a warm, humid environment - to develop the signature minty-cinnamon aromatics without over-fermenting. The leaves are then fired to halt oxidation and dried. The large-leaf Burmese genetics produce sizeable, wiry leaves that are distinctly different from Chinese small-leaf black teas.

Tasting Notes

Appearance

Long, wiry, dark copper-brown leaves with golden tips. The leaves are noticeably larger than most Chinese black teas, reflecting the Burmese large-leaf parentage. When brewed, the liquor is a brilliant, clear reddish-amber with an almost jewel-like sparkle.

Aroma

Unmistakable and unique - fresh spearmint and cinnamon dominate, supported by malt, honey, and a subtle tropical fruit note. This distinctive minty-spice aroma is Ruby 18's signature and the reason it became famous. No other tea in the world smells quite like this.

Taste

Bold yet refined - the first sip delivers a warm cinnamon-malt sweetness, followed by a surprising cool mint freshness that's unlike anything in the tea world. The body is full and smooth without any harshness. Notes of dark honey, ripe stone fruit, and a hint of eucalyptus develop. The finish is long, sweet, and cooling. Remarkably, the tea drinks beautifully both straight and with milk.

Brewing Guide

Western Style

  • Leaf: 3g per 200ml
  • Water: 90–95°C (194–203°F)
  • Time: 3–5 minutes
  • Infusions: 2–3 infusions

Gongfu Style

  • Leaf: 5g per 100ml
  • Water: 90°C (194°F)
  • Time: 45s first, +15s each subsequent
  • Infusions: 5–6 infusions

Step-by-step

  1. Heat the water. Bring water to 90–95°C (194–203°F). Slightly lower than boiling preserves the delicate mint aromatics. Tip: Using a temperature just below boiling keeps the minty top notes vibrant.
  2. Measure the leaves. Add 3g for western-style (200ml) or 5g for gongfu (100ml). The large leaves need room to expand. Tip: Use a wider brewing vessel - the big leaves need space to fully open.
  3. First steep. Steep 3–5 minutes for western, 45 seconds for gongfu. Watch for the brilliant reddish-amber liquor. Tip: Breathe in the steam - the mint-cinnamon aroma is most intense right after pouring.
  4. Additional steeps. Western style yields 2–3 infusions, gongfu 5–6. Increase time by 15–30 seconds each round. Tip: Try it with a splash of milk - Ruby 18 is one of the rare premium teas that pairs beautifully with dairy.

Health Benefits

  • Full oxidation produces theaflavins and thearubigins with cardiovascular benefits
  • The wild Taiwanese tea genetics contribute unique polyphenol profiles
  • Contains moderate caffeine for sustained energy
  • The menthol-like compounds may provide respiratory comfort

Food Pairings

  • Taiwanese sun cakes (tai yang bing) - the buttery pastry complements the malty sweetness
  • Cinnamon pastries and spiced desserts - mirrors the tea's natural spice
  • Dark chocolate with mint inclusions
  • Scones with clotted cream - the British tradition works beautifully with this Taiwanese tea
  • Excellent with a splash of milk and honey for afternoon tea

Buying Guide

What to look for

  • Genuine Ruby 18 should be labeled TTES #18 or 紅玉 (Hong Yu)
  • Large, wiry leaves with visible golden tips indicate premium grade
  • The distinctive mint-cinnamon aroma should be evident even from dry leaves
  • Sun Moon Lake / Yuchi Township origin is the most sought-after

Quality indicators

  • Fish Pond (Yuchi) in Nantou County is the original and premier production area
  • Hand-picked one-bud-two-leaf is superior to machine-harvested
  • The liquor should be brilliantly clear, not cloudy
  • Competition-grade Ruby 18 is available from the Yuchi Farmers' Association

Price range: $15–25 for standard quality, $30–50 for hand-picked premium, $60–100+ for competition-grade

Storage: Store airtight in a cool, dark place. Consume within 1–2 years for peak minty freshness, though the tea remains good for longer with some evolution of flavor.

Fun Facts

  • Ruby 18 took over 50 years to develop - the breeding program began in the 1940s but the cultivar wasn't officially released until 1999.
  • The distinctive mint-cinnamon character comes from the wild Taiwanese tea (Camellia formosensis) parent - a genetic trait not found in any other cultivated tea.
  • Sun Moon Lake was originally a tea-growing region during the Japanese colonial era, producing black tea for export to the West.
  • Ruby 18 is sometimes called the 'Bordeaux of Black Tea' for its complex, terroir-driven character.
  • The tea literally saved Taiwan's black tea industry - production had nearly ceased before Ruby 18's popularity revived interest.

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